This invention relates an apparatus for converting solar energy into electrical energy and for transmitting and/or receiving high-frequency electromagnetic waves, comprising at least one solar cell having electrodes in the form of electrically conducting contacts and an antenna provided with at least one antenna element.
Known apparatuses of this kind consist of an interconnected assembly, which includes at least one solar cell, an antenna element and an electronic component in the form of a display, an image or sound converter, a signal processing circuit, or the like. The antenna in one variant consists of a metal plate connected to the component, while a plurality of solar cells are arranged like a frame surrounding the component (JP-A 10 242 443). In another variant the antenna is a frame antenna surrounding the component and the solar cell arrangement and being e.g. formed by a conductor arranged on the surface of the component (WO 97/44 707). Such arrangements are used in portable radios, televisions, pocket computers or similar devices, for example.
It is further known, especially in satellite technology, to operate large area antennae with the aid of solar cell modules arranged separately therefrom (U.S. Pat. No. 5,642,122, JP-A-08 274 527). The solar cell modules and antennae are in fact frequently connected physically to one another, but for the rest they are usually used as spatially and functionally separate components. This is true also in cases in which the antennae are in the form of parabolic antennae and have a reflector consisting of a metal grating, behind which a solar cell module is arranged (JP-A 9 135 110), or in which individual solar cells are mounted between antenna elements spaced from one another, in order to form a planar antenna (JP-A 6 029 734). Finally, in apparatuses comprising a plurality of antenna elements, a plurality of solar cells arranged below said elements and a conductive layer arranged between the elements and the cells, the function of the solar cells is restricted, because the cells are partially covered by the antenna elements (JP-A-10 270 925).
The described apparatuses require a comparatively large amount of space, in spite of the combination of solar cells and antenna elements in interconnected assemblies, resulting from the sum of the space requirements of the individual components. Apart from this the solar cells are at least partially covered by antenna elements, which affects their function when they are needed to provide the most cost-effective generation of current in efficient photo-voltaic units for example.
The invention is, therefore, based on the object to design the apparatus of the kind specified above such that it is suitable in particular for use in photo-voltaic devices.
A further object of this invention is to give the apparatus a space-saving design.
Yet another object of this invention is to combine parts of the solar elements and the antennae in order to obtain in a simple construction an integrated assembly.
These and other objects are solved in accordance with this invention by means of an apparatus of the kind specified above and being characterized in that said antenna element is formed by at least one of said contacts of the solar cell.
The apparatus according to the invention provides the advantage that solar cells and antennae are not merely combined in an integrated assembly but that electrically conductive contacts, which are in any case present in a solar cell or solar cell arrangement to allow them to operate are used as antenna elements at the same time. The additional fitting of antenna elements can thus be completely avoided.
Further advantageous features of the invention appear from the dependent claims.